Hi, I am a neuroscientist developing a study on pain responses. For this purpose I wish to use a Peltier element to produce a controlled level of heat. I have purchased a 3x3cm elements rated between 5v - 16v max with 3.3 amp max current. I wish to be able to control heat output. In the lab we have a variable DC current source. What I need to know is whether any additional control elements will need to be introduced into the circuit to produce the desired effect? This is a methodology that has been used previously in psychology studies so I know it must work but have been unable to find any constructional details in the published literature. I would be most grateful for any assistance anyone can provide. Many thanks.